1. Field of the Invention
The present invention relates to a lens barrel that can be switched to a projected state in which the lens barrel is projected in an optical axis direction and a stored state in which the lens barrel is stored.
2. Description of the Related Art
Heretofore, a so-called retractable lens barrel is known that can be switched to a projected state (a photographable state) in which the lens barrel is projected in an optical axis direction and a stored state (a retracted state) in which the lens barrel is stored. In the retractable lens barrel, it is variously proposed that a predetermined lens be retreated in the retracted state or that the lens be inserted into a lens shutter to reduce a length of the retracted lens barrel.
In a retractable lens barrel disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-347615, the lens shutter can be moved in the optical axis direction with respect to a lens unit. Moreover, in the retracted state, an opening of the lens shutter is opened, and the lens unit is inserted into the opening to reduce a dimension of the retracted lens barrel in the optical axis direction.
In a retractable lens barrel disclosed in Japanese Patent Application Laid-Open No. 2003-315861, in the retracted state, a part of optical elements is retreated at a position away from an optical axis of another optical element, and the other optical element is positioned at a retreated space to reduce the dimension of the retracted lens barrel in the optical axis direction.
A lens barrel disclosed in Japanese Patent Application Laid-Open No. 2005-004232 includes a position control cam which extends in parallel with an optical axis, and a retreated lens unit support frame which can be moved with respect to this position control cam in the optical axis direction. Moreover, when the position control cam comes close to the retreated lens unit support frame, the position control cam engages with a cam follower of the retreated lens unit support frame, and the retreated lens unit support frame is rotated to a retracted position. When the retreated lens unit support frame is retreated in this manner, thickness of the retracted lens barrel in the optical axis direction can be reduced. It is to be noted that the position control cam is disposed at an image pickup device holding frame which holds an image pickup device such as a CCD. Owing to such restrictions, a lens space between the retreated lens and a lens disposed before or after the retreated lens cannot be reduced.